wifi: ath12k: Move hal_tx and hal_rx to wifi7 directory

wifi: ath12k: Move hal_tx and hal_rx to wifi7 directory

Move architecture-specific files hal_rx.c and hal_tx.c into the wifi7
directory as part of a broader effort to separate common and hardware
-specific code into distinct modules. This modularization enables reuse
of the common driver components across multiple hardware architectures.

The relocated files remain part of ath12k.ko temporarily, until the
corresponding infra for movement to the ath12k_wifi7.ko arrives in
upcoming patches.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.4.1-00199-QCAHKSWPL_SILICONZ-1
Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3

Signed-off-by: Pavankumar Nandeshwar <quic_pnandesh@quicinc.com>
Signed-off-by: Ripan Deuri <quic_rdeuri@quicinc.com>
Reviewed-by: Vasanthakumar Thiagarajan <vasanthakumar.thiagarajan@oss.qualcomm.com>
Reviewed-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>
Link: https://patch.msgid.link/20250828173553.3341351-2-quic_rdeuri@quicinc.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>